disabled gpu::sum, gpu::minMax, gpu:Canny until fix crash.

fixed FernDescriptorMatch; optimized keypoint regions matching in detector/descriptor evaluation; added CalonderDescriptorExtractor to evaluation tests

possible fix for ticket 380 (should not hurt camera calibration engine, as the fix only affects non-planar objects)

minor fix of matrix_operations.cpp.

added calib3d dependency of highgui, to visualize checkerboard detector work, and probably other algorithms

added RGB <-> XYZ color conversion.
gpu morphology minor fix.

warnings in cxcore
added graphcut wrapper

added gpu::cvtColor for BGR5x5 <-> BGR and BGR5x5 <-> Gray.

added gpu exp, log, magnitude, based on NPP.
updated setTo with new NPP functions.
minor fix in tests and comments.